Effects of low‑frequency noise from wind turbines on heart rate variability in healthy individuals
Nature.com|Chun‑Hsiang Chiu, Shih‑Chun Candice Lung, Nathan Chen, Jing‑Shiang Hwang & Ming‑Chien Mark Tsou|September 8, 2021
This important study looked at changes in heart rate variability (HRV) when exposed to low frequency noise produced by wind turbines. HRV does not mean heart rate. Rather HRV measures (in milliseconds) the changes in time between successive heartbeats. The HRV is an important measure of a person's Autonomic Nervous System (ANS). The HRV is also referred to as inter-beat intervals, RR intervals, NN intervals, etc. This study found that when exposed to turbine low frequency noise the test subjects showed lower HRV levels. Lower resting-state HRV scores can indicate the body is under stress and lacks the ability to recover or has an exhaustion of recovery capacity.
This important study looked at changes in heart rate variability (HRV) when exposed to low frequency noise produced by wind turbines. HRV does not mean heart rate. Rather HRV measures (in milliseconds) the changes in time between successive heartbeats. The HRV is an important measure of a person's Autonomic Nervous System (ANS). The HRV is also referred to as inter-beat intervals, RR intervals, NN intervals, etc. This study found that when exposed to turbine low frequency noise the test subjects showed lower HRV levels. Lower resting-state HRV scores can indicate the body is under stress and lacks the ability to recover or has an exhaustion of recovery capacity.
Abstract
Wind turbines generate low-frequency noise (LFN, 20–200 Hz), which poses health risks to nearby residents. This study aimed to assess heart rate variability (HRV) responses to LFN exposure and to evaluate the LFN exposure (dB, LAeq) inside households located near wind turbines. Thirty subjects living within a 500 m radius of wind turbines were recruited. The field campaigns for LFN (LAeq) and HRV monitoring were carried out in July and December 2018. A generalized additive mixed model was employed to evaluate the relationship between HRV changes and LFN. The results suggested that the standard deviations of all the normal to normal R–R intervals were reduced significantly, by 3.39%, with a 95% CI = (0.15%, 6.52%) per 7.86 dB (LAeq) of LFN in the exposure range of 38.2–57.1 dB (LAeq). The indoor LFN exposure (LAeq) ranged between 30.7 and 43.4 dB (LAeq) at a distance of 124–330 m from wind turbines. Moreover, households built with concrete and equipped with airtight windows showed the highest LFN difference of 13.7 dB between indoors and outdoors. In view of the adverse health impacts of LFN exposure, there should be regulations on the requisite distances of wind turbines from residential communities for health protection.
Conclusions
LFN from wind turbines is potentially annoying to residents living nearby and affects human health. This study assessed the response of HRV indicators (SDNN and LF/HF) to LFN exposure and evaluated the LFN exposure inside households located near wind turbines. The results showed the association of changes in HRV with LFN exposure and an SDNN reduction of 0.43% with an increase of 1 dB (LAeq) in LFN. The households’ average LFN levels were 34.8 ± 6.9 and 43.4 ± 5.7 dB for indoors and outdoors, respectively. In addition, the average indoor LFN levels at nighttime in four of the seven households monitored were above 30 dB (LAeq), the threshold for good sleep quality. Taiwan has a high population density, and wind farms have been set up near residential communities. In view of the adverse health impacts of exposure to turbine-generated LFN, it is recommended that the government set regulations on the requisite distances of wind turbines from residences, for houses near wind turbines to be equipped with airtight windows for sound insulation, and for residents living in close proximity to wind turbines to have their windows closed most of the time to reduce LFN transmission.
